I am seeing a new thread pop up nearly everyday about not getting the early access code. Hopefully this stays on the front page somehow.
If you pre ordered Stormblood from the Playstation Store, you will not recieve an email with a code.
You will get your reciept email from Sony. You wilk automatically be registered. This has been confirmed by Squenix customer service, and Bayhone in the SB sticky thread.